// 	Name: 10.c
//	Description: Chapter 5 project 10
//	Author: StableGenius
//	Date: 2020-05-07
//	Email: feng@dongfa.pro

#include <stdio.h>

int main(void)
{
	int grade;
	
	printf("Enter numerical grade: ");
	scanf("%d", &grade);
	
	if (grade > 100 || grade < 0){
		printf("invalid numerical grade!\n");
	} else {
		switch (grade / 10){
			case 10: // go through
			case 9:
				printf("A\n");
				break;
			case 8:
				printf("B\n");
				break;
			case 7:
				printf("C\n");
				break;
			case 6:
				printf("D\n");
				break;
			default:
				printf("F\n");
				break;
		}
	}
    
	return 0;
}
